The present invention relates to the discovery, identification, and characterization of novel human polynucleotides encoding a kinase which share sequence similarity with animal kinases. The invention encompasses the described polynucleotides, host cell expression systems, the encoded proteins, fusion proteins, polypeptides and peptides, antibodies to the encoded proteins and peptides, and genetically engineered animals that either lack or overexpress the disclosed genes, antagonists and agonists of the proteins, and other compounds that modulate the expression or activity of the proteins encoded by the disclosed genes, which can be used for diagnosis, drug screening, clinical trial monitoring, the treatment of diseases and disorders, and cosmetic or nutriceutical applications.
Kinases mediate the phosphorylation of a wide variety of proteins and compounds in the cell. In conjunction with phosphatases, kinases are involved in a range of regulatory pathways. Given the physiological importance of kinases, they have been subject to intense scrutiny and are proven drug targets.
The present invention relates to the discovery, identification, and characterization of nucleotides that encode novel a human kinase and the corresponding amino acid sequence of this protein. The novel human kinases (NHK) described for the first time herein shares structural similarity with animal kinases, including, but not limited to, receptor tyrosine kinases and especially kinases of the membrane-associated guanylate kinase (MAGUK) family. The described NHK encoding sequences define a novel kinase having homologues and orthologs across a range of phyla and species.
The novel human polynucleotide described herein, encode an open reading frame (ORF) of 455 amino acids in length (see SEQ ID NO: 2).
The invention also encompasses agonists and antagonists of the described NHK, including small molecules, large molecules, mutant NHKs, or portions thereof, that compete with native NHK, peptides, and antibodies, as well as nucleotide sequences that can be used to inhibit the expression of the described NHK (e.g., antisense and ribozyme molecules, and open reading frame or regulatory sequence replacement constructs) or to enhance the expression of the described NHK (e.g., expression constructs that place the described polynucleotide under the control of a strong promoter system), and transgenic animals that express a NHK sequence, or xe2x80x9cknock-outsxe2x80x9d (which can be conditional) that do not express a functional NHK. Such knock-out mice can be produced in several ways, one of which involves the use of mouse embryonic stem cell (xe2x80x9cES cellsxe2x80x9d) lines that contain gene trap mutations in a murine homolog the described NHK. When the unique NHK sequences described in SEQ ID NOS:1-2 are xe2x80x9cknocked-outxe2x80x9d they provide a method of identifying phenotypic expression of the particular gene as well as a method of assigning function to previously unknown genes. In addition, animals in which the unique NHK sequences described in SEQ ID NOS:1-2 are xe2x80x9cknocked-outxe2x80x9d provide a unique source in which to elicit antibodies to homologous and orthologous proteins which would have been previously viewed by the immune system as xe2x80x9cselfxe2x80x9d and therefore would have failed to elicit significant antibody responses.
Additionally, the unique NHK sequences described in SEQ ID NOS:1-2 are useful for the identification of protein coding sequence and mapping a unique gene to a particular chromosome. These sequences identify actual, biologically verified, and therefore relevant, exon splice junctions as opposed to those that may have been bioinformatically predicted from genomic sequence alone. The sequences of the present invention are also useful as additional DNA markers for restriction fragment length polymorphism (RFLP) analysis, and in forensic biology.
Further, the present invention also relates to processes for identifying compounds that modulate, i.e., act as agonists or antagonists, of NHK expression and/or NHK activity that utilize purified preparations of the described NHK and/or NHK products, or cells expressing the same. Such compounds can be used as therapeutic agents for the treatment of any of a wide variety of symptoms associated with biological disorders or imbalances.